Whamcloud - gitweb
LU-1866 osd: ancillary work for initial OI scrub
[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_scrub.c
index 0e6382f..62d5c6f 100644 (file)
@@ -20,7 +20,7 @@
  * GPL HEADER END
  */
 /*
- * Copyright (c) 2012 Whamcloud, Inc.
+ * Copyright (c) 2012, Intel Corporation.
  */
 /*
  * lustre/osd-ldiskfs/osd_scrub.c
 
 #define HALF_SEC       (CFS_HZ >> 1)
 
+#define SCRUB_NEXT_BREAK       1 /* exit current loop and process next group */
+#define SCRUB_NEXT_CONTINUE    2 /* skip current object and process next bit */
+#define SCRUB_NEXT_EXIT        3 /* exit all the loops */
+#define SCRUB_NEXT_WAIT        4 /* wait for free cache slot */
+#define SCRUB_NEXT_CRASH       5 /* simulate system crash during OI scrub */
+#define SCRUB_NEXT_FATAL       6 /* simulate failure during OI scrub */
+#define SCRUB_NEXT_NOSCRUB     7 /* new created object, no scrub on it */
+#define SCRUB_NEXT_NOLMA       8 /* the inode has no FID-in-LMA */
+
+/* misc functions */
+
 static inline struct osd_device *osd_scrub2dev(struct osd_scrub *scrub)
 {
        return container_of0(scrub, struct osd_device, od_scrub);
@@ -60,6 +71,93 @@ static inline struct super_block *osd_scrub2sb(struct osd_scrub *scrub)
        return osd_sb(osd_scrub2dev(scrub));
 }
 
+static inline int osd_scrub_has_window(struct osd_scrub *scrub,
+                                      struct osd_otable_cache *ooc)
+{
+       return scrub->os_pos_current < ooc->ooc_pos_preload + SCRUB_WINDOW_SIZE;
+}
+
+static int osd_scrub_refresh_mapping(struct osd_thread_info *info,
+                                    struct osd_device *dev,
+                                    const struct lu_fid *fid,
+                                    const struct osd_inode_id *id, int ops)
+{
+       struct lu_fid         *oi_fid = &info->oti_fid2;
+       struct osd_inode_id   *oi_id  = &info->oti_id2;
+       struct iam_container  *bag;
+       struct iam_path_descr *ipd;
+       handle_t              *jh;
+       int                    rc;
+       ENTRY;
+
+       fid_cpu_to_be(oi_fid, fid);
+       osd_id_pack(oi_id, id);
+       jh = ldiskfs_journal_start_sb(osd_sb(dev),
+                                     osd_dto_credits_noquota[ops]);
+       if (IS_ERR(jh)) {
+               rc = PTR_ERR(jh);
+               CERROR("%.16s: fail to start trans for scrub store: rc = %d\n",
+                      LDISKFS_SB(osd_sb(dev))->s_es->s_volume_name, rc);
+               RETURN(rc);
+       }
+
+       bag = &osd_fid2oi(dev, fid)->oi_dir.od_container;
+       ipd = osd_idx_ipd_get(info->oti_env, bag);
+       if (unlikely(ipd == NULL)) {
+               ldiskfs_journal_stop(jh);
+               CERROR("%.16s: fail to get ipd for scrub store\n",
+                      LDISKFS_SB(osd_sb(dev))->s_es->s_volume_name);
+               RETURN(-ENOMEM);
+       }
+
+       if (ops == DTO_INDEX_UPDATE) {
+               rc = iam_update(jh, bag, (const struct iam_key *)oi_fid,
+                               (struct iam_rec *)oi_id, ipd);
+       } else {
+               rc = iam_insert(jh, bag, (const struct iam_key *)oi_fid,
+                               (struct iam_rec *)oi_id, ipd);
+               if (rc == -EEXIST) {
+                       rc = 1;
+                       /* XXX: There are trouble things when adding OI
+                        *      mapping for IGIF object, which may cause
+                        *      multiple objects to be mapped to the same
+                        *      IGIF formatted FID. Consider the following
+                        *      situations:
+                        *
+                        *      1) The MDT is upgrading from 1.8 device.
+                        *      The OI scrub generates IGIF FID1 for the
+                        *      OBJ1 and adds the OI mapping.
+                        *
+                        *      2) For some reason, the OI scrub does not
+                        *      process all the IGIF objects completely.
+                        *
+                        *      3) The MDT is backuped and restored against
+                        *      this device.
+                        *
+                        *      4) When the MDT mounts up, the OI scrub will
+                        *      try to rebuild the OI files. For some IGIF
+                        *      object, OBJ2, which was not processed by the
+                        *      OI scrub before the backup/restore, and the
+                        *      new generated IGIF formatted FID may be just
+                        *      the FID1, the same as OBJ1.
+                        *
+                        *      Under such case, the OI scrub cannot know how
+                        *      to generate new FID for the OBJ2.
+                        *
+                        *      Currently, we do nothing for that. One possible
+                        *      solution is to generate new normal FID for the
+                        *      conflict object.
+                        *
+                        *      Anyway, it is rare, only exists in theory. */
+               }
+       }
+       osd_ipd_put(info->oti_env, bag, ipd);
+       ldiskfs_journal_stop(jh);
+       RETURN(rc);
+}
+
+/* OI_scrub file ops */
+
 static void osd_scrub_file_to_cpu(struct scrub_file *des,
                                  struct scrub_file *src)
 {
@@ -157,6 +255,8 @@ void osd_scrub_file_reset(struct osd_scrub *scrub, __u8 *uuid, __u64 flags)
        sf->sf_items_updated = 0;
        sf->sf_items_failed = 0;
        sf->sf_items_updated_prior = 0;
+       sf->sf_items_noscrub = 0;
+       sf->sf_items_igif = 0;
 }
 
 static int osd_scrub_file_load(struct osd_scrub *scrub)
@@ -214,7 +314,7 @@ int osd_scrub_file_store(struct osd_scrub *scrub)
 
        osd_scrub_file_to_le(&scrub->os_file_disk, &scrub->os_file);
        rc = osd_ldiskfs_write_record(scrub->os_inode, &scrub->os_file_disk,
-                                     len, &pos, jh);
+                                     len, 0, &pos, jh);
        ldiskfs_journal_stop(jh);
        if (rc != 0)
                CERROR("%.16s: fail to store scrub file, expected = %d, "
@@ -227,6 +327,8 @@ int osd_scrub_file_store(struct osd_scrub *scrub)
        return rc;
 }
 
+/* OI scrub APIs */
+
 static int osd_scrub_prep(struct osd_device *dev)
 {
        struct osd_scrub     *scrub  = &dev->od_scrub;
@@ -236,7 +338,7 @@ static int osd_scrub_prep(struct osd_device *dev)
        int                   rc;
        ENTRY;
 
-       cfs_down_write(&scrub->os_rwsem);
+       down_write(&scrub->os_rwsem);
        if (flags & SS_SET_FAILOUT)
                sf->sf_param |= SP_FAILOUT;
 
@@ -245,7 +347,7 @@ static int osd_scrub_prep(struct osd_device *dev)
 
        if (flags & SS_RESET)
                osd_scrub_file_reset(scrub,
-                       LDISKFS_SB(osd_sb(dev))->s_es->s_uuid, sf->sf_flags);
+                       LDISKFS_SB(osd_sb(dev))->s_es->s_uuid, 0);
 
        if (flags & SS_AUTO) {
                scrub->os_full_speed = 1;
@@ -259,11 +361,12 @@ static int osd_scrub_prep(struct osd_device *dev)
 
        scrub->os_in_prior = 0;
        scrub->os_waiting = 0;
+       scrub->os_paused = 0;
        scrub->os_new_checked = 0;
        if (sf->sf_pos_last_checkpoint != 0)
                sf->sf_pos_latest_start = sf->sf_pos_last_checkpoint + 1;
        else
-               sf->sf_pos_latest_start = LDISKFS_FIRST_INO(osd_sb(dev));
+               sf->sf_pos_latest_start = LDISKFS_FIRST_INO(osd_sb(dev)) + 1;
 
        scrub->os_pos_current = sf->sf_pos_latest_start;
        sf->sf_status = SS_SCANNING;
@@ -271,66 +374,59 @@ static int osd_scrub_prep(struct osd_device *dev)
        sf->sf_time_last_checkpoint = sf->sf_time_latest_start;
        rc = osd_scrub_file_store(scrub);
        if (rc == 0) {
-               cfs_spin_lock(&scrub->os_lock);
+               spin_lock(&scrub->os_lock);
                thread_set_flags(thread, SVC_RUNNING);
-               cfs_spin_unlock(&scrub->os_lock);
+               spin_unlock(&scrub->os_lock);
                cfs_waitq_broadcast(&thread->t_ctl_waitq);
        }
-       cfs_up_write(&scrub->os_rwsem);
+       up_write(&scrub->os_rwsem);
 
        RETURN(rc);
 }
 
 static int
-osd_scrub_error(struct osd_device *dev, struct osd_inode_id *lid, int rc)
-{
-       struct osd_scrub  *scrub = &dev->od_scrub;
-       struct scrub_file *sf    = &scrub->os_file;
-
-       cfs_down_write(&scrub->os_rwsem);
-       scrub->os_new_checked++;
-       sf->sf_items_failed++;
-       if (sf->sf_pos_first_inconsistent == 0 ||
-           sf->sf_pos_first_inconsistent > lid->oii_ino)
-               sf->sf_pos_first_inconsistent = lid->oii_ino;
-       cfs_up_write(&scrub->os_rwsem);
-       return sf->sf_param & SP_FAILOUT ? rc : 0;
-}
-
-static int
-osd_scrub_check_update(struct osd_thread_info *info,  struct osd_device *dev,
-                      struct osd_idmap_cache *oic)
+osd_scrub_check_update(struct osd_thread_info *info, struct osd_device *dev,
+                      struct osd_idmap_cache *oic, int val)
 {
        struct osd_scrub             *scrub  = &dev->od_scrub;
        struct scrub_file            *sf     = &scrub->os_file;
+       struct lu_fid                *fid    = &oic->oic_fid;
+       struct osd_inode_id          *lid    = &oic->oic_lid;
        struct osd_inode_id          *lid2   = &info->oti_id;
-       struct lu_fid                *oi_fid = &info->oti_fid;
-       struct osd_inode_id          *oi_id  = &info->oti_id;
-       handle_t                     *jh     = NULL;
        struct osd_inconsistent_item *oii    = NULL;
        struct inode                 *inode  = NULL;
-       struct lu_fid                *fid    = &oic->oic_fid;
-       struct osd_inode_id          *lid    = &oic->oic_lid;
-       struct iam_container         *bag;
-       struct iam_path_descr        *ipd;
        int                           ops    = DTO_INDEX_UPDATE;
        int                           idx;
        int                           rc;
        ENTRY;
 
+       down_write(&scrub->os_rwsem);
+       scrub->os_new_checked++;
+       if (val < 0)
+               GOTO(out, rc = val);
+
        if (scrub->os_in_prior)
                oii = cfs_list_entry(oic, struct osd_inconsistent_item,
                                     oii_cache);
 
-       cfs_down_write(&scrub->os_rwsem);
-       scrub->os_new_checked++;
        if (lid->oii_ino < sf->sf_pos_latest_start && oii == NULL)
                GOTO(out, rc = 0);
 
-       if (oii != NULL && oii->oii_insert)
+       if (fid_is_igif(fid))
+               sf->sf_items_igif++;
+
+       if (val == SCRUB_NEXT_NOLMA && !dev->od_handle_nolma)
+               GOTO(out, rc = 0);
+
+       if ((oii != NULL && oii->oii_insert) || (val == SCRUB_NEXT_NOLMA))
                goto iget;
 
-       rc = osd_oi_lookup(info, dev, fid, lid2);
+       /* XXX: Currently, no FID-in-LMA for OST object, so osd_oi_lookup()
+        *      wihtout checking FLD is enough.
+        *
+        *      It should be updated if FID-in-LMA for OSD object introduced
+        *      in the future. */
+       rc = osd_oi_lookup(info, dev, fid, lid2, false);
        if (rc != 0) {
                if (rc != -ENOENT)
                        GOTO(out, rc);
@@ -346,51 +442,25 @@ iget:
                }
 
                /* Prevent the inode to be unlinked during OI scrub. */
-               cfs_mutex_lock(&inode->i_mutex);
+               mutex_lock(&inode->i_mutex);
                if (unlikely(inode->i_nlink == 0)) {
-                       cfs_mutex_unlock(&inode->i_mutex);
+                       mutex_unlock(&inode->i_mutex);
                        iput(inode);
                        GOTO(out, rc = 0);
                }
 
                ops = DTO_INDEX_INSERT;
                idx = osd_oi_fid2idx(dev, fid);
+               sf->sf_flags |= SF_RECREATED | SF_INCONSISTENT;
                if (unlikely(!ldiskfs_test_bit(idx, sf->sf_oi_bitmap)))
                        ldiskfs_set_bit(idx, sf->sf_oi_bitmap);
-               sf->sf_flags |= SF_RECREATED;
        } else if (osd_id_eq(lid, lid2)) {
-                       GOTO(out, rc = 0);
-       }
-
-       sf->sf_flags |= SF_INCONSISTENT;
-       fid_cpu_to_be(oi_fid, fid);
-       osd_id_pack(oi_id, &oic->oic_lid);
-       jh = ldiskfs_journal_start_sb(osd_sb(dev),
-                               osd_dto_credits_noquota[ops]);
-       if (IS_ERR(jh)) {
-               rc = PTR_ERR(jh);
-               CERROR("%.16s: fail to start trans for scrub store, rc = %d\n",
-                      LDISKFS_SB(osd_sb(dev))->s_es->s_volume_name, rc);
-               GOTO(out, rc);
-       }
-
-       bag = &osd_fid2oi(dev, fid)->oi_dir.od_container;
-       ipd = osd_idx_ipd_get(info->oti_env, bag);
-       if (unlikely(ipd == NULL)) {
-               ldiskfs_journal_stop(jh);
-               CERROR("%.16s: fail to get ipd for scrub store\n",
-                       LDISKFS_SB(osd_sb(dev))->s_es->s_volume_name);
-               GOTO(out, rc = -ENOMEM);
+               GOTO(out, rc = 0);
+       } else {
+               sf->sf_flags |= SF_INCONSISTENT;
        }
 
-       if (ops == DTO_INDEX_UPDATE)
-               rc = iam_update(jh, bag, (const struct iam_key *)oi_fid,
-                               (struct iam_rec *)oi_id, ipd);
-       else
-               rc = iam_insert(jh, bag, (const struct iam_key *)oi_fid,
-                               (struct iam_rec *)oi_id, ipd);
-       osd_ipd_put(info->oti_env, bag, ipd);
-       ldiskfs_journal_stop(jh);
+       rc = osd_scrub_refresh_mapping(info, dev, fid, lid, ops);
        if (rc == 0) {
                if (scrub->os_in_prior)
                        sf->sf_items_updated_prior++;
@@ -401,37 +471,43 @@ iget:
        GOTO(out, rc);
 
 out:
-       if (rc != 0) {
+       if (rc < 0) {
                sf->sf_items_failed++;
                if (sf->sf_pos_first_inconsistent == 0 ||
                    sf->sf_pos_first_inconsistent > lid->oii_ino)
                        sf->sf_pos_first_inconsistent = lid->oii_ino;
+       } else {
+               rc = 0;
        }
 
        if (ops == DTO_INDEX_INSERT) {
-               cfs_mutex_unlock(&inode->i_mutex);
+               mutex_unlock(&inode->i_mutex);
                iput(inode);
        }
-       cfs_up_write(&scrub->os_rwsem);
+       up_write(&scrub->os_rwsem);
 
        if (oii != NULL) {
                LASSERT(!cfs_list_empty(&oii->oii_list));
 
-               cfs_spin_lock(&scrub->os_lock);
+               spin_lock(&scrub->os_lock);
                cfs_list_del_init(&oii->oii_list);
-               cfs_spin_unlock(&scrub->os_lock);
+               spin_unlock(&scrub->os_lock);
                OBD_FREE_PTR(oii);
        }
        RETURN(sf->sf_param & SP_FAILOUT ? rc : 0);
 }
 
-static int do_osd_scrub_checkpoint(struct osd_scrub *scrub)
+static int osd_scrub_checkpoint(struct osd_scrub *scrub)
 {
        struct scrub_file *sf = &scrub->os_file;
        int                rc;
-       ENTRY;
 
-       cfs_down_write(&scrub->os_rwsem);
+       if (likely(cfs_time_before(cfs_time_current(),
+                                  scrub->os_time_next_checkpoint) ||
+                  scrub->os_new_checked == 0))
+               return 0;
+
+       down_write(&scrub->os_rwsem);
        sf->sf_items_checked += scrub->os_new_checked;
        scrub->os_new_checked = 0;
        sf->sf_pos_last_checkpoint = scrub->os_pos_current;
@@ -439,18 +515,9 @@ static int do_osd_scrub_checkpoint(struct osd_scrub *scrub)
        sf->sf_run_time += cfs_duration_sec(cfs_time_current() + HALF_SEC -
                                            scrub->os_time_last_checkpoint);
        rc = osd_scrub_file_store(scrub);
-       cfs_up_write(&scrub->os_rwsem);
-
-       RETURN(rc);
-}
+       up_write(&scrub->os_rwsem);
 
-static inline int osd_scrub_checkpoint(struct osd_scrub *scrub)
-{
-       if (unlikely(cfs_time_beforeq(scrub->os_time_next_checkpoint,
-                                     cfs_time_current()) &&
-                    scrub->os_new_checked > 0))
-               return do_osd_scrub_checkpoint(scrub);
-       return 0;
+       return rc;
 }
 
 static void osd_scrub_post(struct osd_scrub *scrub, int result)
@@ -458,10 +525,10 @@ static void osd_scrub_post(struct osd_scrub *scrub, int result)
        struct scrub_file *sf = &scrub->os_file;
        ENTRY;
 
-       cfs_down_write(&scrub->os_rwsem);
-       cfs_spin_lock(&scrub->os_lock);
+       down_write(&scrub->os_rwsem);
+       spin_lock(&scrub->os_lock);
        thread_set_flags(&scrub->os_thread, SVC_STOPPING);
-       cfs_spin_unlock(&scrub->os_lock);
+       spin_unlock(&scrub->os_lock);
        if (scrub->os_new_checked > 0) {
                sf->sf_items_checked += scrub->os_new_checked;
                scrub->os_new_checked = 0;
@@ -475,7 +542,10 @@ static void osd_scrub_post(struct osd_scrub *scrub, int result)
                sf->sf_time_last_complete = sf->sf_time_last_checkpoint;
                sf->sf_success_count++;
        } else if (result == 0) {
-               sf->sf_status = SS_PAUSED;
+               if (scrub->os_paused)
+                       sf->sf_status = SS_PAUSED;
+               else
+                       sf->sf_status = SS_STOPPED;
        } else {
                sf->sf_status = SS_FAILED;
        }
@@ -486,15 +556,12 @@ static void osd_scrub_post(struct osd_scrub *scrub, int result)
                CERROR("%.16s: fail to osd_scrub_post, rc = %d\n",
                       LDISKFS_SB(osd_scrub2sb(scrub))->s_es->s_volume_name,
                       result);
-       cfs_up_write(&scrub->os_rwsem);
+       up_write(&scrub->os_rwsem);
 
        EXIT;
 }
 
-#define SCRUB_NEXT_BREAK       1 /* exit current loop and process next group */
-#define SCRUB_NEXT_CONTINUE    2 /* skip current object and process next bit */
-#define SCRUB_NEXT_EXIT        3 /* exit all the loops */
-#define SCRUB_NEXT_WAIT        4 /* wait for free cache slot */
+/* iteration engine */
 
 struct osd_iit_param {
        struct super_block *sb;
@@ -516,12 +583,6 @@ typedef int (*osd_iit_exec_policy)(struct osd_thread_info *info,
                                   struct osd_idmap_cache *oic,
                                   int *noslot, int rc);
 
-static inline int osd_scrub_has_window(struct osd_scrub *scrub,
-                                      struct osd_otable_cache *ooc)
-{
-       return scrub->os_pos_current < ooc->ooc_pos_preload + SCRUB_WINDOW_SIZE;
-}
-
 static int osd_iit_next(struct osd_iit_param *param, __u32 *pos)
 {
        param->offset = ldiskfs_find_next_bit(param->bitmap->b_data,
@@ -537,13 +598,14 @@ static int osd_iit_next(struct osd_iit_param *param, __u32 *pos)
 
 static int osd_iit_iget(struct osd_thread_info *info, struct osd_device *dev,
                        struct lu_fid *fid, struct osd_inode_id *lid, __u32 pos,
-                       struct super_block *sb, struct inode **pinode)
+                       struct super_block *sb, bool scrub)
 {
-       struct inode *inode;
-       int           rc;
+       struct lustre_mdt_attrs *lma   = &info->oti_mdt_attrs;
+       struct inode            *inode;
+       int                      rc;
 
        osd_id_gen(lid, pos, OSD_OII_NOGEN);
-       inode = osd_iget_fid(info, dev, lid, fid);
+       inode = osd_iget(info, dev, lid);
        if (IS_ERR(inode)) {
                rc = PTR_ERR(inode);
                /* The inode may be removed after bitmap searching, or the
@@ -556,8 +618,38 @@ static int osd_iit_iget(struct osd_thread_info *info, struct osd_device *dev,
                return rc;
        }
 
-       *pinode = inode;
-       return 0;
+       /* If the inode has no OI mapping, then it is special locally used,
+        * should be invisible to OI scrub or up layer LFSCK. */
+       if (ldiskfs_test_inode_state(inode, LDISKFS_STATE_LUSTRE_NO_OI)) {
+               iput(inode);
+               return SCRUB_NEXT_CONTINUE;
+       }
+
+       if (scrub &&
+           ldiskfs_test_inode_state(inode, LDISKFS_STATE_LUSTRE_NOSCRUB)) {
+               /* Only skip it for the first OI scrub accessing. */
+               ldiskfs_clear_inode_state(inode, LDISKFS_STATE_LUSTRE_NOSCRUB);
+               iput(inode);
+               return SCRUB_NEXT_NOSCRUB;
+       }
+
+       rc = osd_get_lma(info, inode, &info->oti_obj_dentry, lma);
+       if (rc == 0) {
+               if (!scrub) {
+                       if (!fid_is_client_visible(&lma->lma_self_fid))
+                               rc = SCRUB_NEXT_CONTINUE;
+                       else
+                               *fid = lma->lma_self_fid;
+               }
+       } else if (rc == -ENODATA) {
+               lu_igif_build(fid, inode->i_ino, inode->i_generation);
+               if (scrub)
+                       rc = SCRUB_NEXT_NOLMA;
+               else
+                       rc = 0;
+       }
+       iput(inode);
+       return rc;
 }
 
 static int osd_scrub_next(struct osd_thread_info *info, struct osd_device *dev,
@@ -568,9 +660,28 @@ static int osd_scrub_next(struct osd_thread_info *info, struct osd_device *dev,
        struct ptlrpc_thread *thread = &scrub->os_thread;
        struct lu_fid        *fid;
        struct osd_inode_id  *lid;
-       struct inode         *inode;
        int                   rc;
 
+       if (OBD_FAIL_CHECK(OBD_FAIL_OSD_SCRUB_DELAY) && cfs_fail_val > 0) {
+               struct l_wait_info lwi;
+
+               lwi = LWI_TIMEOUT(cfs_time_seconds(cfs_fail_val), NULL, NULL);
+               l_wait_event(thread->t_ctl_waitq,
+                            !cfs_list_empty(&scrub->os_inconsistent_items) ||
+                            !thread_is_running(thread),
+                            &lwi);
+       }
+
+       if (OBD_FAIL_CHECK(OBD_FAIL_OSD_SCRUB_CRASH)) {
+               spin_lock(&scrub->os_lock);
+               thread_set_flags(thread, SVC_STOPPING);
+               spin_unlock(&scrub->os_lock);
+               return SCRUB_NEXT_CRASH;
+       }
+
+       if (OBD_FAIL_CHECK(OBD_FAIL_OSD_SCRUB_FATAL))
+               return SCRUB_NEXT_FATAL;
+
        if (unlikely(!thread_is_running(thread)))
                return SCRUB_NEXT_EXIT;
 
@@ -595,13 +706,7 @@ static int osd_scrub_next(struct osd_thread_info *info, struct osd_device *dev,
        fid = &(*oic)->oic_fid;
        lid = &(*oic)->oic_lid;
        rc = osd_iit_iget(info, dev, fid, lid,
-                         scrub->os_pos_current, param->sb, &inode);
-       if (rc != 0)
-               return rc;
-
-       if (!fid_is_norm(fid) || inode->i_state & I_LUSTRE_NOSCRUB)
-               rc = SCRUB_NEXT_CONTINUE;
-       iput(inode);
+                         scrub->os_pos_current, param->sb, true);
        return rc;
 }
 
@@ -612,7 +717,6 @@ static int osd_preload_next(struct osd_thread_info *info,
        struct osd_otable_cache *ooc    = &dev->od_otable_it->ooi_cache;
        struct osd_scrub        *scrub;
        struct ptlrpc_thread    *thread;
-       struct inode            *inode;
        int                      rc;
 
        rc = osd_iit_next(param, &ooc->ooc_pos_preload);
@@ -628,12 +732,10 @@ static int osd_preload_next(struct osd_thread_info *info,
        rc = osd_iit_iget(info, dev,
                          &ooc->ooc_cache[ooc->ooc_producer_idx].oic_fid,
                          &ooc->ooc_cache[ooc->ooc_producer_idx].oic_lid,
-                         ooc->ooc_pos_preload, param->sb, &inode);
+                         ooc->ooc_pos_preload, param->sb, false);
        /* If succeed, it needs to move forward; otherwise up layer LFSCK may
         * ignore the failure, so it still need to skip the inode next time. */
        ooc->ooc_pos_preload = param->gbase + ++(param->offset);
-       if (rc == 0)
-               iput(inode);
        return rc;
 }
 
@@ -643,6 +745,7 @@ static int osd_scrub_exec(struct osd_thread_info *info, struct osd_device *dev,
 {
        struct l_wait_info       lwi    = { 0 };
        struct osd_scrub        *scrub  = &dev->od_scrub;
+       struct scrub_file       *sf     = &scrub->os_file;
        struct ptlrpc_thread    *thread = &scrub->os_thread;
        struct osd_otable_it    *it     = dev->od_otable_it;
        struct osd_otable_cache *ooc    = it ? &it->ooi_cache : NULL;
@@ -652,14 +755,15 @@ static int osd_scrub_exec(struct osd_thread_info *info, struct osd_device *dev,
                goto next;
        case SCRUB_NEXT_WAIT:
                goto wait;
+       case SCRUB_NEXT_NOSCRUB:
+               down_write(&scrub->os_rwsem);
+               scrub->os_new_checked++;
+               sf->sf_items_noscrub++;
+               up_write(&scrub->os_rwsem);
+               goto next;
        }
 
-       LASSERTF(rc <= 0, "unexpected rc = %d\n", rc);
-
-       if (rc != 0)
-               rc = osd_scrub_error(dev, &oic->oic_lid, rc);
-       else
-               rc = osd_scrub_check_update(info, dev, oic);
+       rc = osd_scrub_check_update(info, dev, oic, rc);
        if (rc != 0)
                return rc;
 
@@ -723,6 +827,7 @@ static int osd_preload_exec(struct osd_thread_info *info,
 }
 
 #define SCRUB_IT_ALL   1
+#define SCRUB_IT_CRASH 2
 
 static int osd_inode_iteration(struct osd_thread_info *info,
                               struct osd_device *dev, __u32 max, int preload)
@@ -779,6 +884,12 @@ static int osd_inode_iteration(struct osd_thread_info *info,
                        case SCRUB_NEXT_EXIT:
                                brelse(param.bitmap);
                                RETURN(0);
+                       case SCRUB_NEXT_CRASH:
+                               brelse(param.bitmap);
+                               RETURN(SCRUB_IT_CRASH);
+                       case SCRUB_NEXT_FATAL:
+                               brelse(param.bitmap);
+                               RETURN(-EINVAL);
                        }
 
                        rc = exec(info, dev, &param, oic, &noslot, rc);
@@ -797,6 +908,32 @@ next_group:
        RETURN(0);
 }
 
+static int osd_otable_it_preload(const struct lu_env *env,
+                                struct osd_otable_it *it)
+{
+       struct osd_device       *dev   = it->ooi_dev;
+       struct osd_scrub        *scrub = &dev->od_scrub;
+       struct osd_otable_cache *ooc   = &it->ooi_cache;
+       int                      rc;
+       ENTRY;
+
+       rc = osd_inode_iteration(osd_oti_get(env), dev,
+                                OSD_OTABLE_IT_CACHE_SIZE, 1);
+       if (rc == SCRUB_IT_ALL)
+               it->ooi_all_cached = 1;
+
+       CDEBUG(D_LFSCK, "OSD pre-loaded: max = %u, preload = %u, rc = %d\n",
+              le32_to_cpu(LDISKFS_SB(osd_sb(dev))->s_es->s_inodes_count),
+              ooc->ooc_pos_preload, rc);
+
+       if (scrub->os_waiting && osd_scrub_has_window(scrub, ooc)) {
+               scrub->os_waiting = 0;
+               cfs_waitq_broadcast(&scrub->os_thread.t_ctl_waitq);
+       }
+
+       RETURN(rc < 0 ? rc : ooc->ooc_cached_items);
+}
+
 static int osd_scrub_main(void *args)
 {
        struct lu_env         env;
@@ -841,6 +978,8 @@ static int osd_scrub_main(void *args)
               scrub->os_start_flags, scrub->os_pos_current);
 
        rc = osd_inode_iteration(osd_oti_get(&env), dev, ~0U, 0);
+       if (unlikely(rc == SCRUB_IT_CRASH))
+               GOTO(out, rc = -EINVAL);
        GOTO(post, rc);
 
 post:
@@ -860,13 +999,15 @@ out:
        lu_env_fini(&env);
 
 noenv:
-       cfs_spin_lock(&scrub->os_lock);
+       spin_lock(&scrub->os_lock);
        thread_set_flags(thread, SVC_STOPPED);
        cfs_waitq_broadcast(&thread->t_ctl_waitq);
-       cfs_spin_unlock(&scrub->os_lock);
+       spin_unlock(&scrub->os_lock);
        return rc;
 }
 
+/* OI scrub start/stop */
+
 static int do_osd_scrub_start(struct osd_device *dev, __u32 flags)
 {
        struct osd_scrub     *scrub  = &dev->od_scrub;
@@ -877,18 +1018,21 @@ static int do_osd_scrub_start(struct osd_device *dev, __u32 flags)
 
 again:
        /* os_lock: sync status between stop and scrub thread */
-       cfs_spin_lock(&scrub->os_lock);
+       spin_lock(&scrub->os_lock);
        if (thread_is_running(thread)) {
-               cfs_spin_unlock(&scrub->os_lock);
+               spin_unlock(&scrub->os_lock);
                RETURN(-EALREADY);
        } else if (unlikely(thread_is_stopping(thread))) {
-               cfs_spin_unlock(&scrub->os_lock);
+               spin_unlock(&scrub->os_lock);
                l_wait_event(thread->t_ctl_waitq,
                             thread_is_stopped(thread),
                             &lwi);
                goto again;
        }
-       cfs_spin_unlock(&scrub->os_lock);
+       spin_unlock(&scrub->os_lock);
+
+       if (scrub->os_file.sf_status == SS_COMPLETED)
+               flags |= SS_RESET;
 
        scrub->os_start_flags = flags;
        thread_set_flags(thread, 0);
@@ -908,17 +1052,13 @@ again:
 
 int osd_scrub_start(struct osd_device *dev)
 {
-       __u32 flags = SS_AUTO;
-       int   rc;
+       int rc;
        ENTRY;
 
-       if (dev->od_scrub.os_file.sf_status == SS_COMPLETED)
-               flags |= SS_RESET;
-
        /* od_otable_mutex: prevent curcurrent start/stop */
-       cfs_mutex_lock(&dev->od_otable_mutex);
-       rc = do_osd_scrub_start(dev, flags);
-       cfs_mutex_unlock(&dev->od_otable_mutex);
+       mutex_lock(&dev->od_otable_mutex);
+       rc = do_osd_scrub_start(dev, SS_AUTO);
+       mutex_unlock(&dev->od_otable_mutex);
 
        RETURN(rc == -EALREADY ? 0 : rc);
 }
@@ -929,29 +1069,32 @@ static void do_osd_scrub_stop(struct osd_scrub *scrub)
        struct l_wait_info    lwi    = { 0 };
 
        /* os_lock: sync status between stop and scrub thread */
-       cfs_spin_lock(&scrub->os_lock);
+       spin_lock(&scrub->os_lock);
        if (!thread_is_init(thread) && !thread_is_stopped(thread)) {
                thread_set_flags(thread, SVC_STOPPING);
-               cfs_spin_unlock(&scrub->os_lock);
+               spin_unlock(&scrub->os_lock);
                cfs_waitq_broadcast(&thread->t_ctl_waitq);
                l_wait_event(thread->t_ctl_waitq,
                             thread_is_stopped(thread),
                             &lwi);
                /* Do not skip the last lock/unlock, which can guarantee that
                 * the caller cannot return until the OI scrub thread exit. */
-               cfs_spin_lock(&scrub->os_lock);
+               spin_lock(&scrub->os_lock);
        }
-       cfs_spin_unlock(&scrub->os_lock);
+       spin_unlock(&scrub->os_lock);
 }
 
 static void osd_scrub_stop(struct osd_device *dev)
 {
        /* od_otable_mutex: prevent curcurrent start/stop */
-       cfs_mutex_lock(&dev->od_otable_mutex);
+       mutex_lock(&dev->od_otable_mutex);
+       dev->od_scrub.os_paused = 1;
        do_osd_scrub_stop(&dev->od_scrub);
-       cfs_mutex_unlock(&dev->od_otable_mutex);
+       mutex_unlock(&dev->od_otable_mutex);
 }
 
+/* OI scrub setup/cleanup */
+
 static const char osd_scrub_name[] = "OI_scrub";
 
 int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
@@ -971,17 +1114,16 @@ int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
        int                         rc     = 0;
        ENTRY;
 
+       memset(scrub, 0, sizeof(*scrub));
        OBD_SET_CTXT_MAGIC(ctxt);
        ctxt->pwdmnt = dev->od_mnt;
        ctxt->pwd = dev->od_mnt->mnt_root;
        ctxt->fs = get_ds();
 
        cfs_waitq_init(&scrub->os_thread.t_ctl_waitq);
-       cfs_init_rwsem(&scrub->os_rwsem);
-       cfs_spin_lock_init(&scrub->os_lock);
+       init_rwsem(&scrub->os_rwsem);
+       spin_lock_init(&scrub->os_lock);
        CFS_INIT_LIST_HEAD(&scrub->os_inconsistent_items);
-       if (get_mount_flags(dev->od_mount->lmi_sb) & LMD_FLG_NOSCRUB)
-               scrub->os_no_scrub = 1;
 
        push_ctxt(&saved, ctxt, NULL);
        filp = filp_open(osd_scrub_name, O_RDWR | O_CREAT, 0644);
@@ -991,6 +1133,8 @@ int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
        scrub->os_inode = igrab(filp->f_dentry->d_inode);
        filp_close(filp, 0);
        pop_ctxt(&saved, ctxt, NULL);
+       ldiskfs_set_inode_state(scrub->os_inode,
+                               LDISKFS_STATE_LUSTRE_NO_OI);
 
        rc = osd_scrub_file_load(scrub);
        if (rc == -ENOENT) {
@@ -1012,7 +1156,7 @@ int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
        if (sf->sf_pos_last_checkpoint != 0)
                scrub->os_pos_current = sf->sf_pos_last_checkpoint + 1;
        else
-               scrub->os_pos_current = LDISKFS_FIRST_INO(sb);
+               scrub->os_pos_current = LDISKFS_FIRST_INO(sb) + 1;
 
        if (dirty != 0) {
                rc = osd_scrub_file_store(scrub);
@@ -1045,8 +1189,9 @@ int osd_scrub_setup(const struct lu_env *env, struct osd_device *dev)
                }
        }
 
-       if (rc == 0 && !scrub->os_no_scrub &&
-           ((sf->sf_status == SS_CRASHED &&
+       if (rc == 0 && !dev->od_noscrub &&
+           ((sf->sf_status == SS_PAUSED) ||
+            (sf->sf_status == SS_CRASHED &&
              sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT | SF_AUTO)) ||
             (sf->sf_status == SS_INIT &&
              sf->sf_flags & (SF_RECREATED | SF_INCONSISTENT))))
@@ -1070,6 +1215,8 @@ void osd_scrub_cleanup(const struct lu_env *env, struct osd_device *dev)
                osd_oi_fini(osd_oti_get(env), dev);
 }
 
+/* object table based iteration APIs */
+
 static struct dt_it *osd_otable_it_init(const struct lu_env *env,
                                       struct dt_object *dt, __u32 attr,
                                       struct lustre_capa *capa)
@@ -1084,7 +1231,7 @@ static struct dt_it *osd_otable_it_init(const struct lu_env *env,
        ENTRY;
 
        /* od_otable_mutex: prevent curcurrent init/fini */
-       cfs_mutex_lock(&dev->od_otable_mutex);
+       mutex_lock(&dev->od_otable_mutex);
        if (dev->od_otable_it != NULL)
                GOTO(out, it = ERR_PTR(-EALREADY));
 
@@ -1122,7 +1269,7 @@ static struct dt_it *osd_otable_it_init(const struct lu_env *env,
        GOTO(out, it);
 
 out:
-       cfs_mutex_unlock(&dev->od_otable_mutex);
+       mutex_unlock(&dev->od_otable_mutex);
        return (struct dt_it *)it;
 }
 
@@ -1132,16 +1279,29 @@ static void osd_otable_it_fini(const struct lu_env *env, struct dt_it *di)
        struct osd_device    *dev = it->ooi_dev;
 
        /* od_otable_mutex: prevent curcurrent init/fini */
-       cfs_mutex_lock(&dev->od_otable_mutex);
+       mutex_lock(&dev->od_otable_mutex);
        do_osd_scrub_stop(&dev->od_scrub);
        LASSERT(dev->od_otable_it == it);
 
        dev->od_otable_it = NULL;
-       cfs_mutex_unlock(&dev->od_otable_mutex);
+       mutex_unlock(&dev->od_otable_mutex);
        OBD_FREE_PTR(it);
 }
 
 /**
+ * XXX: Temporary used to notify otable iteration to be paused.
+ */
+static void osd_otable_it_put(const struct lu_env *env, struct dt_it *di)
+{
+       struct osd_device *dev = ((struct osd_otable_it *)di)->ooi_dev;
+
+       /* od_otable_mutex: prevent curcurrent init/fini */
+       mutex_lock(&dev->od_otable_mutex);
+       dev->od_scrub.os_paused = 1;
+       mutex_unlock(&dev->od_otable_mutex);
+}
+
+/**
  * Set the OSD layer iteration start position as the specified key.
  *
  * The LFSCK out of OSD layer does not know the detail of the key, so if there
@@ -1174,32 +1334,6 @@ static int osd_otable_it_get(const struct lu_env *env,
        RETURN(0);
 }
 
-static int osd_otable_it_preload(const struct lu_env *env,
-                                struct osd_otable_it *it)
-{
-       struct osd_device       *dev   = it->ooi_dev;
-       struct osd_scrub        *scrub = &dev->od_scrub;
-       struct osd_otable_cache *ooc   = &it->ooi_cache;
-       int                      rc;
-       ENTRY;
-
-       rc = osd_inode_iteration(osd_oti_get(env), dev,
-                                OSD_OTABLE_IT_CACHE_SIZE, 1);
-       if (rc == SCRUB_IT_ALL)
-               it->ooi_all_cached = 1;
-
-       CDEBUG(D_LFSCK, "OSD pre-loaded: max = %u, preload = %u, rc = %d\n",
-              le32_to_cpu(LDISKFS_SB(osd_sb(dev))->s_es->s_inodes_count),
-              ooc->ooc_pos_preload, rc);
-
-       if (scrub->os_waiting && osd_scrub_has_window(scrub, ooc)) {
-               scrub->os_waiting = 0;
-               cfs_waitq_broadcast(&scrub->os_thread.t_ctl_waitq);
-       }
-
-       RETURN(rc < 0 ? rc : ooc->ooc_cached_items);
-}
-
 static int osd_otable_it_next(const struct lu_env *env, struct dt_it *di)
 {
        struct osd_otable_it    *it     = (struct osd_otable_it *)di;
@@ -1286,8 +1420,8 @@ static int osd_otable_it_load(const struct lu_env *env,
        if (it->ooi_user_ready)
                return 0;
 
-       if (ooc->ooc_pos_preload < LDISKFS_FIRST_INO(osd_sb(dev)))
-               ooc->ooc_pos_preload = LDISKFS_FIRST_INO(osd_sb(dev));
+       if (ooc->ooc_pos_preload <= LDISKFS_FIRST_INO(osd_sb(dev)))
+               ooc->ooc_pos_preload = LDISKFS_FIRST_INO(osd_sb(dev)) + 1;
        it->ooi_user_ready = 1;
        if (!scrub->os_full_speed)
                cfs_waitq_broadcast(&scrub->os_thread.t_ctl_waitq);
@@ -1300,6 +1434,7 @@ const struct dt_index_operations osd_otable_ops = {
        .dio_it = {
                .init     = osd_otable_it_init,
                .fini     = osd_otable_it_fini,
+               .put      = osd_otable_it_put,
                .get      = osd_otable_it_get,
                .next     = osd_otable_it_next,
                .key      = osd_otable_it_key,
@@ -1308,3 +1443,267 @@ const struct dt_index_operations osd_otable_ops = {
                .load     = osd_otable_it_load,
        }
 };
+
+/* high priority inconsistent items list APIs */
+
+int osd_oii_insert(struct osd_device *dev, struct osd_idmap_cache *oic,
+                  int insert)
+{
+       struct osd_inconsistent_item *oii;
+       struct osd_scrub             *scrub  = &dev->od_scrub;
+       struct ptlrpc_thread         *thread = &scrub->os_thread;
+       int                           wakeup = 0;
+       ENTRY;
+
+       OBD_ALLOC_PTR(oii);
+       if (unlikely(oii == NULL))
+               RETURN(-ENOMEM);
+
+       CFS_INIT_LIST_HEAD(&oii->oii_list);
+       oii->oii_cache = *oic;
+       oii->oii_insert = insert;
+
+       spin_lock(&scrub->os_lock);
+       if (unlikely(!thread_is_running(thread))) {
+               spin_unlock(&scrub->os_lock);
+               OBD_FREE_PTR(oii);
+               RETURN(-EAGAIN);
+       }
+
+       if (cfs_list_empty(&scrub->os_inconsistent_items))
+               wakeup = 1;
+       cfs_list_add_tail(&oii->oii_list, &scrub->os_inconsistent_items);
+       spin_unlock(&scrub->os_lock);
+
+       if (wakeup != 0)
+               cfs_waitq_broadcast(&thread->t_ctl_waitq);
+
+       RETURN(0);
+}
+
+int osd_oii_lookup(struct osd_device *dev, const struct lu_fid *fid,
+                  struct osd_inode_id *id)
+{
+       struct osd_scrub             *scrub = &dev->od_scrub;
+       struct osd_inconsistent_item *oii;
+       ENTRY;
+
+       spin_lock(&scrub->os_lock);
+       cfs_list_for_each_entry(oii, &scrub->os_inconsistent_items, oii_list) {
+               if (lu_fid_eq(fid, &oii->oii_cache.oic_fid)) {
+                       *id = oii->oii_cache.oic_lid;
+                       spin_unlock(&scrub->os_lock);
+                       RETURN(0);
+               }
+       }
+       spin_unlock(&scrub->os_lock);
+
+       RETURN(-ENOENT);
+}
+
+/* OI scrub dump */
+
+static const char *scrub_status_names[] = {
+       "init",
+       "scanning",
+       "completed",
+       "failed",
+       "stopped",
+       "paused",
+       "crashed",
+       NULL
+};
+
+static const char *scrub_flags_names[] = {
+       "recreated",
+       "inconsistent",
+       "auto",
+       NULL
+};
+
+static const char *scrub_param_names[] = {
+       "failout",
+       NULL
+};
+
+static int scrub_bits_dump(char **buf, int *len, int bits, const char *names[],
+                          const char *prefix)
+{
+       int save = *len;
+       int flag;
+       int rc;
+       int i;
+
+       rc = snprintf(*buf, *len, "%s:%c", prefix, bits != 0 ? ' ' : '\n');
+       if (rc <= 0)
+               return -ENOSPC;
+
+       *buf += rc;
+       *len -= rc;
+       for (i = 0, flag = 1; bits != 0; i++, flag = 1 << i) {
+               if (flag & bits) {
+                       bits &= ~flag;
+                       rc = snprintf(*buf, *len, "%s%c", names[i],
+                                     bits != 0 ? ',' : '\n');
+                       if (rc <= 0)
+                               return -ENOSPC;
+
+                       *buf += rc;
+                       *len -= rc;
+               }
+       }
+       return save - *len;
+}
+
+static int scrub_time_dump(char **buf, int *len, __u64 time, const char *prefix)
+{
+       int rc;
+
+       if (time != 0)
+               rc = snprintf(*buf, *len, "%s: "LPU64" seconds\n", prefix,
+                             cfs_time_current_sec() - time);
+       else
+               rc = snprintf(*buf, *len, "%s: N/A\n", prefix);
+       if (rc <= 0)
+               return -ENOSPC;
+
+       *buf += rc;
+       *len -= rc;
+       return rc;
+}
+
+static int scrub_pos_dump(char **buf, int *len, __u64 pos, const char *prefix)
+{
+       int rc;
+
+       if (pos != 0)
+               rc = snprintf(*buf, *len, "%s: "LPU64"\n", prefix, pos);
+       else
+               rc = snprintf(*buf, *len, "%s: N/A\n", prefix);
+       if (rc <= 0)
+               return -ENOSPC;
+
+       *buf += rc;
+       *len -= rc;
+       return rc;
+}
+
+int osd_scrub_dump(struct osd_device *dev, char *buf, int len)
+{
+       struct osd_scrub  *scrub   = &dev->od_scrub;
+       struct scrub_file *sf      = &scrub->os_file;
+       __u64              checked;
+       __u64              speed;
+       int                save    = len;
+       int                ret     = -ENOSPC;
+       int                rc;
+
+       down_read(&scrub->os_rwsem);
+       rc = snprintf(buf, len,
+                     "name: OI_scrub\n"
+                     "magic: 0x%x\n"
+                     "oi_files: %d\n"
+                     "status: %s\n",
+                     sf->sf_magic, (int)sf->sf_oi_count,
+                     scrub_status_names[sf->sf_status]);
+       if (rc <= 0)
+               goto out;
+
+       buf += rc;
+       len -= rc;
+       rc = scrub_bits_dump(&buf, &len, sf->sf_flags, scrub_flags_names,
+                            "flags");
+       if (rc < 0)
+               goto out;
+
+       rc = scrub_bits_dump(&buf, &len, sf->sf_param, scrub_param_names,
+                            "param");
+       if (rc < 0)
+               goto out;
+
+       rc = scrub_time_dump(&buf, &len, sf->sf_time_last_complete,
+                            "time_since_last_completed");
+       if (rc < 0)
+               goto out;
+
+       rc = scrub_time_dump(&buf, &len, sf->sf_time_latest_start,
+                            "time_since_latest_start");
+       if (rc < 0)
+               goto out;
+
+       rc = scrub_time_dump(&buf, &len, sf->sf_time_last_checkpoint,
+                            "time_since_last_checkpoint");
+       if (rc < 0)
+               goto out;
+
+       rc = scrub_pos_dump(&buf, &len, sf->sf_pos_latest_start,
+                           "latest_start_position");
+       if (rc < 0)
+               goto out;
+
+       rc = scrub_pos_dump(&buf, &len, sf->sf_pos_last_checkpoint,
+                           "last_checkpoint_position");
+       if (rc < 0)
+               goto out;
+
+       rc = scrub_pos_dump(&buf, &len, sf->sf_pos_first_inconsistent,
+                           "first_failure_position");
+       if (rc < 0)
+               goto out;
+
+       checked = sf->sf_items_checked + scrub->os_new_checked;
+       rc = snprintf(buf, len,
+                     "checked: "LPU64"\n"
+                     "updated: "LPU64"\n"
+                     "failed: "LPU64"\n"
+                     "prior_updated: "LPU64"\n"
+                     "noscrub: "LPU64"\n"
+                     "igif: "LPU64"\n"
+                     "success_count: %u\n",
+                     checked, sf->sf_items_updated, sf->sf_items_failed,
+                     sf->sf_items_updated_prior, sf->sf_items_noscrub,
+                     sf->sf_items_igif, sf->sf_success_count);
+       if (rc <= 0)
+               goto out;
+
+       buf += rc;
+       len -= rc;
+       speed = checked;
+       if (thread_is_running(&scrub->os_thread)) {
+               cfs_duration_t duration = cfs_time_current() -
+                                         scrub->os_time_last_checkpoint;
+               __u64 new_checked = scrub->os_new_checked * CFS_HZ;
+               __u32 rtime = sf->sf_run_time +
+                             cfs_duration_sec(duration + HALF_SEC);
+
+               if (duration != 0)
+                       do_div(new_checked, duration);
+               if (rtime != 0)
+                       do_div(speed, rtime);
+               rc = snprintf(buf, len,
+                             "run_time: %u seconds\n"
+                             "average_speed: "LPU64" objects/sec\n"
+                             "real-time_speed: "LPU64" objects/sec\n"
+                             "current_position: %u\n",
+                             rtime, speed, new_checked, scrub->os_pos_current);
+       } else {
+               if (sf->sf_run_time != 0)
+                       do_div(speed, sf->sf_run_time);
+               rc = snprintf(buf, len,
+                             "run_time: %u seconds\n"
+                             "average_speed: "LPU64" objects/sec\n"
+                             "real-time_speed: N/A\n"
+                             "current_position: N/A\n",
+                             sf->sf_run_time, speed);
+       }
+       if (rc <= 0)
+               goto out;
+
+       buf += rc;
+       len -= rc;
+       ret = save - len;
+
+out:
+       up_read(&scrub->os_rwsem);
+       return ret;
+}